Japanese find way to make flu vaccine effective for multiple strains

Mar 11 2008

Japanese scientists say they are well on the way to developing influenza vaccines which are effective for multiple strains of the disease, including strains of the bird flu virus.

The researchers from the National Institute of Infectious Diseases say they have developed a substance with the potential to fight multiple strains of influenza.

The substance, a peptide derived from the influenza virus, carries on its surface an antigen, the molecule that triggers a response in the immune system.

Flu vaccines as a rule create antibodies which act against flu viruses, but since the virus surfaces frequently mutate, different vaccines have to be made every year.

The researchers found that when the peptide was injected into mice, it worked against cells infected by multiple strains of influenza, including bird flu, by targeting the inside of the virus, rather than its surface.

The mice tests showed that the method was effective on different strains of the bird flu virus.

The researchers say this stops the virus replicating itself and the next step is to develop a vaccine that works against multiple strains of flu which is safe for humans.

Tetsuya Uchida, a senior investigator at the Institute says it usually takes about five years to develop vaccines for clinical use, but as bird flu is such an emerging issue they hope to develop a vaccine as soon as possible.

The researchers suggest their findings also have the potential to be be applied to create drugs to treat AIDS, tumours and other diseases.

Since bird flu surfaced back in 2003 more than 200 people have died and poultry flocks have been devastated in many countries.

Bird flu remains essentially a disease of birds and most human cases have been the result of close contact with infected birds, however the ongoing worry is that the virus will eventually mutate into a form transferrable between humans.

In the event that does occur the world could be faced with the threat of a pandemic with the potential to kill millions.

Uchida says they will soon start conducting tests using mice implanted with human genes but it could be years before their research is put to practical use as a flu vaccine.

Indonesia has been most affected by bird flu with 105 human deaths to date.

The study was jointly conducted by researchers from the national institute, Hokkaido University, Saitama Medical University and NOF Corp., a chemicals company based in Tokyo.